It's essentially just a pc so should do.
In the ign interview, their interviewer asked that exact question and the steam guys basically said it will.
But I bet there's a caveat like having to install windows for that, rather than the preinstalled SteamOS which again they said Is completely fine to do.
Seems pretty open but want to hear real world reports first
It would definitely require Windows, unless I've missed something and Gamepass works on Steam too but last time I checked, it was its own thing entirely.